1. Field of the Invention
The present invention relates to a device and a method for rapid roll changes in a six-high roll stand. The device includes a roll change carriage with means for moving the carriage relative to the roll stand parallel to and transversely of the rolling direction, and two retaining components for a pair of work rolls and a pair of intermediate rolls, wherein the retaining components are arranged next to each other and form a side-shifter cassette, wherein the retaining components have guide surfaces for the chocks of the rolls, and wherein the change carriage has in the common rolling plane a device for pushing the rolls in and out.
2. Description of the Related Art
A roll change device for a six-high roll stand having the above-described configuration is disclosed in BR-A-PI 7602387. In this device, the individual rolls together with their chocks are placed by means of a crane in a certain sequence in one of two retaining components arranged next to one another, wherein the rolls are placed in the retaining components in dependence on the next roll change to be carried out. This device has the disadvantage that it is not possible to carry out an exchange of only the set of intermediate rolls. In addition, the known device can only be used if the chocks of the intermediate rolls have smaller dimensions than the chocks of the work rolls.
DE-A-31 23 933 discloses a roll change device for six-high roll stands which has the advantage that the dimensions of the chocks of the set of intermediate rolls does not have to be smaller than the dimensions of the chocks of the set of work rolls. However, this known device also has the disadvantage that complicated and time-consuming reconfiguration and regrouping operations have to be carried out if, instead of the intended change of work rolls, a simultaneous change of the set of intermediate rolls is required. In the known device, it is not possible to carry out only an exchange of the intermediate rolls if that is necessary.
EP 0 112 981 A2 describes a roll change device for six-high roll stands which makes possible either the exchange of the set of work rolls alone or an exchange of the set of work rolls together with the set of intermediate rolls. However, if necessary, it should also be possible to exchange only the set of intermediate rolls. For that purpose, a roll change carriage and a roll loading station are provided. The roll loading station has two retaining departments, wherein one department is capable of receiving only a set of intermediate rolls and the other compartment is capable of only receiving a set of work rolls. This device has the disadvantage that the retaining components of the roll change carriage are constructed so as to be closed toward the top and are only opened at end faces which are located opposite each other. Consequently, it is not possible to exchange all rolls directly by means of a crane out of the roll change carriage or the side-shifter.